Categorization and How to Implement It
To create a category you want to navigate to Posts -> Categories on the left of your Dashboard. In the box on the right there should be one default category named “Uncategorized”. You cannot delete this category because by default, all posts are set with this as their category. To create a new Category, simply go to the section titled “Add New Category” at the left of the screen and enter a name in the first field. The “Slug” is usually the same as the name of the Category, but must be in all lowercase and contain no spaces. The Slug is like a Category version of your Permalinks and is used in Pages to display Posts from the corresponding Category.
The great thing about Categories is that you can create a hierarchy. This is very helpful when you are trying to divide posts into sub-categories. For example, on this site, we have Categories for Standard Users and Administrators. We also have child categories in both parent categories.
Now that you know how to set categories, we can apply one to our first Post. When you go to view your posts, on the right there will be a column that states what category the post is listed under. You can change this two different ways.
The first method is to click “Quick Edit” when you hover over the Post title. This will give you a nice and easy way to change all of the basic settings that apply to the Post. In the center of this new editor, you can select as many categories as you would like the Post to associate with.
The second way to edit categorization is to actually open the Post editor by clicking on the Post title. On the right hand (or underneath the editor depending on screen size) column labelled Categories, you can also select as many categories as you wish.